Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface, showing our newdesign;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof;

FIG. 4 is the fourth image thereof;

FIG. 5 is the fifth image thereof;

FIG. 6 is the sixth image thereof;

FIG. 7 is the seventh image thereof;

FIG. 8 is the eighth image thereof;

FIG. 9 is the ninth image thereof;

FIG. 10 is the tenth image thereof;

FIG. 11 is the eleventh image thereof;

FIG. 12 is the twelfth image thereof;

FIG. 13 is the thirteenth image thereof;

FIG. 14 is the fourteenth image thereof;

FIG. 15 is the fifteenth image thereof;

FIG. 16 is the sixteenth image thereof;

FIG. 17 is the seventeenth image thereof; and,

FIG. 18 is the eighteenth image thereof.

The broken lines illustrate the display screen or portion thereof andform no part of the claimed design. The broken lines illustrate portionsof the transitional graphical user interface and form no part of theclaimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-18. The process or period by whichthe image transitions forms no part of the claimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.